LAUSR

In this issue of Sexually Transmitted Diseases, Zhang and colleagues make two bold assertions. First, they conclude that kissing accounts for more than 70% of gonorrhea in men who have sex with men (MSM). Second, they suggest that a mouthwash with high efficacy against oropharyngeal Neisseria gonorrhoeae could substantially reduce the overall gonorrhea prevalence in MSM. Although anecdotal reports of N. gonorrhoeae transmission through kissing exist, conventional wisdom is that gonorrhea transmission through kissing happens rarely, if at all. It is important to clarify that Zhang and colleagues present no empirical evidence of transmission by kissing. Instead, they conclude that kissing must be an important mode of transmission because, otherwise, their model could not replicate current data on oropharyngeal gonorrhea prevalence among MSM in Australia. Although mathematical models such as that of Zhang and colleagues are vital to the field of sexually transmitted disease (STD) research, a common limitation of these models is a scarcity of data to inform their construction. For science to advance, however, we must be open to new ideas and challenges to conventional wisdom. In fact, over the past decades, we have come to understand that oropharyngeal gonorrhea is more common and more likely to be transmitted to other anatomic sites than was previously thought. Thus, it is conceivable that oropharyngeal infections could play a key role in sustaining gonorrhea in MSM via kissing, as suggested by Zhang and colleagues. If so, it is also plausible that a mouthwash with efficacy against oropharyngeal gonorrhea could have a notable population-level impact on gonorrhea. One of the most useful contributions of their modeling exercise is to highlight the numerous unanswered questions related to how a mouthwash-based intervention may affect community-level gonorrhea prevalence. In the next section, we identify several areas of inquiry that are critical to the development of a more lucid epidemiology of gonorrhea.